Related Experiment Video
Updated: Jun 12, 2025

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Constructing Ultraviolet Nonlinear Optical Crystals with Superior Thermal Stability Based on Organic π-Conjugated
Zhiyuan Lei1,2, Fangrong Liu1, Xuan Pang1
1Chongqing Key Laboratory of inorganic functional materials, College of chemistry, Chongqing Normal University, Chongqing 401331, P.R. China.
Abstract:
In recent years, more and more organic π-conjugated moieties have been screened out to create excellent ultraviolet (UV) and deep-UV nonlinear optical (NLO) crystal materials. However, NLO crystals with organic groups usually exhibit poor thermal stability compared with those of traditional inorganic NLO materials. Herein, the organic group [HCOO], which is similar to traditional planar trigonal π-conjugated anionic groups, was employed to successfully build three UV NLO crystals RE(HCOO)3 (RE = Eu, Gd, and Dy) and two centrosymmetric compounds RE(HCOO)2(OH) (RE = Eu, and Gd) with superior thermal stability. Their structures and properties were further studied and characterized, especially the structure evolutions between noncentrosymmetric RE(HCOO)3 (RE = Eu, Gd, and Dy) and centrosymmetric RE(HCOO)2(OH) (RE = Eu, and Gd), as well as the NLO properties of the three crystals RE(HCOO)3 (RE = Eu, Gd, and Dy).
Related Concept Videos
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent...
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
UV–Vis Spectroscopy: Molecular Electronic Transitions
Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview

